Method of Establishing a Communication System and Communication System Therefor

ABSTRACT

A portable communication system for use in hostile and unknown environments. The system has a base station for control by an operator. The base station dispatches one or more unmanned drones into the hostile environment, where a forward agent, such a robot or investigative person can approach a suspected threat. Each drone has a payload of repeaters to be delivered as necessary to maintain line of sight communication from the forward agent back to the base station. Once delivered, the repeaters are mobile and can autonomously reposition to maintain or optimize line of sight communication. Communications from the forward agent back to the base station are then interpreted and analyzed for further action.

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of provisional U.S.application Ser. No. 63/298,489 filed Jan. 11, 2022, the disclosure ofwhich is incorporated herein by reference.

STATEMENT OF GOVERNMENT INTEREST

The invention described herein may be manufactured and used by and forany governmental purpose without the payment of any royalty.

FIELD OF THE INVENTION

This invention is directed to autonomous, linked communication systemsand more particularly to autonomous, linked communication systems whichare remotely dynamically adjustable to adapt to changing hostileenvironments.

BACKGROUND OF THE INVENTION

Hostile environments can present significant communication challenges,whether indoors or outdoors. A forward agent viewing, recording orengaged with a hostile actor or hostile situation posing a threat mustcommunicate in real time, through a series of repeaters, with commandpersonnel operating at a base station. Such communications typically usewireless signals operating at a 5 GHz frequency or preferably a 2.4 GHzfrequency. Both frequencies rely upon line of sight communications. Butif walls, stairs, boulders, tunnels, vehicles, debris, etc. obstruct theline of sight, communication is lost. Furthermore, an explosion ordeliberate disruption may terminate communication from a previouslyestablished and operable network. For example, cellular signals may notreach the depths of a building or cellular towers may be renderedinoperable by hostile actors.

Pre-installing repeaters between the base station and the forward agentdirectly engaged with the threat is infeasible. The precise location ofthe threat is not known in advance. Electromagnetic interference mayrequire repositioning of the repeaters. Either the forward agent and/orthe threat may change position or relocate to a previously unknownposition.

The forward agent may be a robot, person or drone. If the forward agentis a robot or drone, dynamically installing repeaters in real timeduring advance towards the threat may be infeasible due to the weightpenalty and limited maneuverability. If the forward agent is a person,installing repeaters during advance towards the threat may be infeasibledue to the weight penalty and potential distraction from the mission.Wired systems are infeasible with either such type of forward agent formuch the same reasons and catastrophic sabotage due to cutting the wire.If the forward agent is a drone, a wire connection is infeasible aspotentially interfering with flight. A different approach is needed.

One attempt shown in U.S. Pat. No. 9,100,988 which deploys a mobilerepeater system in a vehicle. But this attempt is infeasible for useindoors and does not provide for remote, dynamic adjustment of therepeater. U.S. Pat. No. 8,638,214 is directed to geolocating and is alsounhelpful for dynamic indoor situations. U.S. Pat. No. 11,157,021 uses adrone to check pre-progammed locations within a building for security,and is likewise unhelpful for hostile situations which are dynamic. U.S.Pat. No. 8,353,373 proposes an expensive network using multiple robotsas radio relays, but does not provide for centralized control of theindividual robots and can be cumbersome when deploying multiple robotsin a congested environment.

None of the attempts in the art overcome the problems of dynamic andremote deployment and positioning of repeaters in a dynamic hostileenvironment. The present invention seeks to overcome these problems.

SUMMARY OF THE INVENTION

In one embodiment the invention comprises a method of establishing acommunication system in a hostile environment. The method comprises thesteps of providing an operably maneuverable drone carrying a pluralityof independently depositable repeaters, providing a base station forcontrolling the drone and controlling the drone from the base station tomaneuver the drone to a plurality of successive repeater stations. Ateach repeater station the drone deposits a repeater thereat, so that arepeater is disposed at each of the repeater stations in order toestablish a mesh of repeaters. The plurality of repeater stationscomprises, in order of deposit, a first repeater station proximate thebase station and having a first repeater, and at least a second repeaterstation having a second repeater, in order, until a nth repeater stationhaving a nth repeater in direct communication with the drone isestablished, whereby the drone can wirelessly transmit a signal from alocation of interest to the nth repeater at the nth repeater station,from said nth repeater to a n−1 repeater at an n−1 repeater station, inturn until said signal is receivable by the first repeater. From thefirst repeater the signal is transmittable to the base station wherebyan operator at the base station can interpret and act upon the signal.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top plan schematic view of a communication system accordingto the present invention having a branched path of repeater stations.

FIG. 2 is a block diagram of the base station hardware.

FIG. 3 is a schematic perspective view of a single tray quadrotor droneaccording to the present invention, shown partially in cutaway andhaving the two front rotors removed for clarity.

FIG. 4 is a block diagram of a flight controller for the drone.

FIG. 5 is a schematic perspective view of a vertically stacked pluraltray dispensing assembly according to the present invention.

FIG. 6A is a top plan view of a six position tray having five repeatersthereon.

FIG. 6B is vertical sectional view of the tray of FIG. 6A, taken alongline 6B-6B and omitting the repeaters for clarity.

FIG. 7 is a scale top plan view of two counter-clockwise rotatable arms,vertically stacked for use with two vertically stacked trays.

FIG. 8 is a schematic exploded top plan view of a three tray dispensingassembly.

FIG. 9A is a top perspective view of a dynamically controllable repeateraccording to the present invention.

FIG. 9B is a bottom perspective view of the repeater of FIG. 9A, shownpartially in cutaway.

FIG. 9C is a schematic bottom plan view of the repeater of FIG. 9A.

FIG. 9D is a schematic side elevational view of the repeater of FIG. 9A.

FIG. 9E is a top perspective view of the repeater of FIG. 9A, having thetop removed for access to the internal components for maintenance.

FIG. 9F is a schematic perspective view of various repeater shells.

FIG. 10A is a block diagram of a control algorithm for the presentinvention.

FIG. 10B is a flow chart of the control algorithm of FIG. 10A.

FIG. 11A is a simulation of a communication system according to thepresent invention showing a top plan view of the initial layout of therepeater stations.

FIG. 11B is a simulation of a communication system according to thepresent invention showing a top plan view of the revised layout of therepeater stations, after adaptation.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 1 , a communication system 20 according to the presentinvention comprises a base station 21, and at least one drone 60 incommunication with the base station 21. The entire communication system20 is portable, for use where a hostile environment may be present. Byportable, it is meant that the entire communication system 20 may beassembled and rapidly deployed in different locations and varioussituations without undue infrastructure or site preparation.

The drone 60 may initially be in direct communication with the basestation 21, and transition to communication through a plurality ofdynamic, depositable, remotely controllable repeaters 30. Thecommunication system 20 further communicates with at least one forwardagent 25. The forward agent 25 may be a battery 36 powered autonomous orremotely controllable robot or a person. The forward agent 25 carries atransceiver 37. The transceiver 37 communicates signals to/from the basestation 21 as described below. The signal from the base station 21through a series of successive repeaters 30 to the drone 60 is referredto as a forward signal. The signal from the drone 60 back through therepeaters 30 in reverse succession to the base station 21 is referred toas the return signal.

One or more operators may be functionally in control of the mission fromthe base station 21. The operators send the drone 60 from the basestation 21 into the mission, it being understood that the drone 60 neednot actually be at the base station 21 to be controlled from the basestation 21.

The forward agent 25, particularly a robotic forward agent 25, may haveany of or any combination of a microphone, speaker, video camera,thermal imaging camera, infrared camera, radiation detector, explosivedetector, GPS, narcotics detector, thermometer, vibration detector,chemical/biological weapons detector, etc. collectively referred to assensors. The return signal may comprise information and data gathered bythe sensors, herein referred to as intelligence. The forward agent 25forms no part of the claimed invention, except as may be specificallyclaimed below.

The base station 21 controls the operation of the drones 60 and therepeaters 30, and may be staffed by one or more operators or optionallybe remotely controlled. The base station 21 is positioned in a safelocation for the staff and can serve as the control center foroperations. The base station 21 receives, and optionally records, realtime wireless signals from the forward agent 25. The base station 21 maybe disposed indoors or outdoors as the situation requires. The basestation 21 dispatches the drone 60 from a secure location to advancetowards the threat. The forward agent 25 may also be dispatched from thebase station 21 or from another location.

Although a single drone 60 is described below, one of the skill willunderstand the communication system 20 is not so limited and may deploya plurality of drones 60. The drone 60 has a dispensing assembly 70 fordispensing repeaters 30 at determinable locations. The drone 60 iscontrolled from the base station 21 and deposits repeaters 30 in a lineof sight configuration as determined to be helpful or necessary duringthe operation. Repeaters 30 may be loaded onto the drone 60 at the basestation 21 or loaded prior to arrival at the hostile environment. Thelocation of repeater stations is not arbitrary, and may be determined byan operator in real time.

In operation, at least one operably maneuverable drone 60 carries aplurality of deliverable repeaters 30 from the base station 21 to aplurality of successive line of site repeater stations in turn andserially deposits a repeater 30 at each of the line of sight repeaterstations from a first repeater 30 to a last repeater 30. Upon depletionof the payload of the plurality of repeaters 30, the drone 60 may returnto the base station 21 for reloading with additional repeaters 30 asnecessary. Alternatively or additionally, additional drones 60 may beused to deliver more repeaters 30, as needed. The plurality of repeaters30 may comprise from 2 to 50 successive repeaters 30. The drone 60 maytraverse the same path back and forth from the base station 21 to one ormore points of interest or traverse different paths, as the changingcircumstances may dictate.

The locations of the repeater stations are usually not predetermined,due to the unknown and changing conditions in a hostile environment. Therepeater stations comprise a first repeater station RS1, and at least asecond repeater station RS2, as deposited in order, until a nth repeaterstation RSn in direct communication with the forward agent 25 isestablished. Using this arrangement, either or both of the drone 60and/or the forward agent 25 can wirelessly transmit a signal from alocation of interest to the repeater 30 Rn at the nth repeater stationRn, closest to the site of interest. The signal is consecutivelytransmitted from the nth repeater 30 Rn to the next (n−1) repeater 30Rn−1 at the next (n−1) repeater station RSn−1, and so on in turn, untilsignal is received by the first repeater 30 R1 located at the firstrepeater station RS1; and transmitted from the first repeater 30 R1 tothe base station 21. Upon receipt at the base station 21, operator caninterpret and act upon the signal. Appropriate actions may includetransmitting a signal back to the forward agent 25. The signal may betransmitted from the base station 21 to the forward agent 25 byreversing this procedure.

The repeaters 30 bilaterally receive and transmit signals in a line ofsight, through other repeaters 30 in order, between the ultimatedestinations of the base station 21 and forward agent 25. As used hereina forward signal is transmitted from the base station 21 through one ormore repeaters 30 to the forward agent 25. A return signal istransmitted from the forward agent 25 back through one or more repeaters30 to the base station 21.

The repeaters 30 are deposited, in sequence, to form a line of sightcommunication from the forward agent 25 to the base station 21. Thenumbering scheme used herein is to designate the repeaters 30 in theorder dispensed from R1, R2, R3 . . . Rm. R1 is the first repeater 30 tobe deposited and is typically closest to the base station 21, R2 is thenext repeater 30 to be deposited, in turn, until the last repeater 30 Rmis deposited closest to and in direct communication with the forwardagent 25. The forward agent 25 transmits a return signal to repeater 30Rm which, in turn, receives the return signal from the forward agent 25and transmits the return signal, in turn, to repeater 30 Rm−1, whichtransmits the return signal to the next repeater 30 Rm−2 and so on untilthe signal is received at repeater 30 R1. The signal from repeater 30 R1is then transmitted to the base station 21 for interpretation andanalysis. Another signal may be transmitted from the base station 21 torepeater 30 R1 where it is received and transmitted to repeater 30 R2and so on until the signal reaches repeater 30 Rm. Repeater 30 Rm thentransmits the signal to the forward agent 25.

The repeaters 30 may be positioned as necessary to optimize signaltransmission as described below. Positioning includes both disposal at aspecific location within the hostile environment and azimuthalorientation at that location.

Referring to FIG. 2 and examining the invention in more detail, the basestation 21 may comprise a laptop, smartphone or other controller forreceiving signals from the forward agent 25 and for converting thesignals for audio/video display to one or more operators. The basestation 21 further comprises a wireless network for communication withthe drone 60, R/C transmitter and preferably a joystick for controllingthe drone 60. If the forward agent 25 is a robot, the base station 21has controls for maneuvering and otherwise operating the robot.

The base station 21 may comprise any mobile computing device such as aphone, tablet, laptop, etc. with adequate control software. Theoperating system preferably has at least 2 GB RAM and a processing speedof 1 GHz. A Hewlett Packard ZBook 17 G5 laptop computer with the LinuxUbuntu operating system and Robot Operating System software has beenfound suitable.

The base station 21 can wirelessly connect to the forward agent's 25on-board control computer via a secure shell (SSH) to remotely initiateautonomous control algorithms, display status messages, telemetryinformation, and/or retrieved intelligence information during themission. The base station 21 may send direct control commands to theforward agent 25 in line of sight, but typically communicates throughthe repeaters 30. An operator can guide the exploration of the forwardagent 25 by providing simple directional commands via an associatedjoystick. The joystick may connect to the base station 21 and multiplecomputing devices via a wired connection or wireless Bluetoothconnection. Typical commands for the drone 60 include velocity requestsforward/back, right/left, and/or up/down. These commands are relayed tothe drone 60 on-board control computer via the repeater 30 network. Thedrone 60 on-board flight algorithms interpret these motion requests andconvert the requests to the necessary motor 35 behaviors to move thedrone 60 as desired. Typical commands for the repeaters 30 includedriving a first motor 35, driving a second motor 35 and driving bothmotors 35. Plural repeaters 30 may be operably and functionally drivenat the same time in response to command signals from the base station21.

Referring to FIG. 3 , the drone 60 may have one or more rotors 62,preferably four rotors 62, a battery 36, a flight controller 32F, anon-board companion computer 32C, a R/C receiver or transceiver 37, atleast one dispensing assembly 70 as described below and a brushlessmotor 35 for each rotor 62. In an operational scenario, the on-boardcomputer may be used for navigation, mapping, intelligence gathering,and further for positioning the repeaters 30, as described below.

The companion computer 32C is able to run Linux (Ubuntu LTS versions16.04 or 18.04), ROS, or equivalent and has at least one USB port.Suitable companion computers 32C are preferably lightweight to conservepayload. The transceiver 37 has at least six channels, communicates overTCP and supports pulse position modulation/SBUS receivers.

Referring to FIG. 4 the flight controller 32F may have an embeddedcircuit board to run ROS flight firmware and perform I/O with theonboard sensors and ESCs. The flight controller 32F preferably hascapability of at least 2000 degrees/second with a 3-axis MEMS gyro plusaccelerometer with a 32 bit processor running at a speed of at least 72MHz. The flight controller 32F preferably has 8 channel RC input forstandard receivers (PWM), such as a PPM Sum receiver (FrSky), or aSpektrum Satellite receiver. A built in FrSky telemetry inverter (sharedwith the main port) and a SBUS inverter are also useful for thisconfiguration. An AfroFlight Naze32, Rev. 6 flight controller 32F hasbeen found suitable.

The boards preferably have at least a 32 bit with CMOS and a M4F CPUrunning at 3.3V/72 MHz. A suitable board is available fromSTMicroelectronics N.V. of Geneva, Switzerland under model numberSTM32F429ZIT6. Another suitable board may have an Arm Cortex-M3 MCU with128 Kbytes of Flash memory, 72 MHz CPU, motor control, USB and CAN, andis also available from STMicroelectronics N.V under model numberSTM32F103x.

ROSflight, available from BYU MAGICC Lab, is used with a companioncomputer 32C mounted on the drone 60 and running ROS. The ROS interfaceis provided by a ROSflight io node. ROSflight packages are installed onboth the companion computer 32C and a base station 21 computer.

The Rosflight io node functions as a bridge between ROSflight and theMAVLink communication with the flight controller 32F. This node is runon the base station 21 computer having the physical serial connection toa flight controller 32F.

The companion computer 32C will run the node that communicates with theflight controller 32F over a serial connection. The base station 21computer uses message and service definitions to call services or tosubscribe and publish to topics.

Configuration of the flight controller 32F is preferably performedthrough a ROS service API as provided by ROSflight io. Sensor data, suchas IMU measurements, are streamed from the flight controller 32F to thecompanion computer 32C and published as ROS topics. Control setpointsmay be sent to the flight controller 32F by publishing to theappropriate ROS topic.

Referring to FIG. 5 , the drone 60 is unmanned and delivers one or morerepeaters 30 to a like number of remote repeater stations. Locationselection for delivery of the repeater 30 to a repeater stationtypically occurs in real time as dictated from the base station 21. Thedrone 60 comprises a copter for flying the drone 60 from a firstlocation to a second location. The drone 60 preferably has capability totravel without interruption from the base station 21 or a locationnearby, to the forward agent 25 while carrying the plural repeater 30payload described below.

The drone 60 has a frame 66 for joining at least one motor 35 and atleast one rotor 62 for powering at least one propeller 63 in rotatablyoperable relationship with a dispensing assembly 70 for dispensingrepeaters 30 therefrom. As discussed below, the dispensing assembly 70is preferably disposed at the bottom of the drone 60 for simplicity andto prevent repeaters 30 from becoming entangled with other componentsupon dispensing.

The frame 66 may comprise at least one cross bar optionally holdingthree or more spaced apart depending legs 34 for resting upon thesupport surface and spacing the bottom tray 71 therefrom. An axiallyrotatable longitudinal shaft 68 is preferably concentrically centered onthe frame 66 and depends from a cross bar of the frame 66 to define alongitudinal axis LA. Each rotatable propeller 63 is driven by a battery36 powered propeller-motor 35 and is rotatable about a respectivepropeller axis. The rotatable shaft 68 is driven by a battery 36 poweredshaft-motor 35. The shaft-motor 35, propeller axes and propeller-motors35 may be mutually axially parallel. For simplicity, the shaft-motor 35and propeller-motor 35 may be identical.

The drone 60 has at least one rotatable propeller 63, which is driven bya battery 36 powered motor 35. While a quadcopter style drone 60 isshown, one of skill will recognize the invention is not so limited andthe drone 60 may comprise any suitable numbers of copters, associatedmotors 35 and associated control system.

The dispensing assembly 70 is joined to the depending legs 34 fordispensing a plurality of repeaters 30 therefrom at determinablelocations. The dispensing assembly 70 preferably comprises at least onecircular tray 71 concentric with the axially rotatable shaft 68 andadapted to carry a plurality of circumferentially spaced repeaters 30thereon. The circular tray 71 has a central blind hole or through holefor accommodating the rotatable shaft 68. The shaft 68 is preferablyrotatable driven by a dedicated shaft motor 35, or may be driven fromone or more of the of the propeller motors 35.

Referring to FIG. 6A and FIG. 6B, the circular tray 71 further has adispensing hole 72 therethrough for receiving and gravity dispensing arepeater 30 therethrough at a desired location and an upstanding lip 73for retaining repeaters 30 within said tray 71 until dispensed throughthe dispensing hole 72. The tray 71 preferably has a low frictionsurface, allowing for smooth movement of the repeaters 30 around theshaft 68 and reducing power requirements. Plural repeaters 30 arecircumferentially disposed on the tray 71 and constrained by the lip 73.The repeaters 30 are preferably round to reduce congestion duringdispensing. Likewise, the dispensing hole 72 is round and slightlylarger than the round repeaters 30 to provide for dispensingtherethrough. One of skill will recognize that other shapes ofdispensing holes 72 may be suitable, provided that the repeaters 30congruently fit through the hole for discharge. For example, thedispensing hole 72, and associated repeaters 30, may be oval,rectangular, crescent shaped, etc.

Optionally, the lip 73 may also depend downwardly from the bottom tray71 of the dispensing assembly 70. Particularly, the lip 73 may dependdownwardly in the longitudinal direction a distance slightly greaterthan the thickness of the repeater 30, as taken in the longitudinaldirection. This arrangement provides the benefit that the drone 60 mayland at a location determined to be suitable for establishing a repeaterstation prior to delivery of the repeater 30. Upon temporarily landingto establish a repeater station, the dispensing assembly 70 dispenses arepeater 30 through the dispensing hole 72 at the hole while the drone60 is stationary and stable.

The depending lip 73 and/or upstanding lip 73 may circumscribe the tray71 to advantageously provide for maximum stability upon temporarilylanding in a hostile environment and containing the repeaters 30 withinthe tray 71, respectively. Alternatively, the depending lip 73 and/orupstanding lip 73 may comprise circumferentially spaced apart segmentsto advantageously conserve weight.

Alternatively, the drone 60 may comprise three or more struts 65, fourstruts 65 being shown, extending downwardly from the bottom of thelowest tray 71. Again, the struts 65 have a length in the longitudinaldirection slightly greater than the thickness of the repeater 30, astaken in the longitudinal direction for landing. This arrangementsimilarly provides the benefit that the drone 60 may temporarily land ata location determined to be suitable for establishing a repeater stationprior to stable and stationary delivery of the repeater 30.

Alternatively, the drone 60 may hover slightly above the support surfacewhile dispensing a repeater 30. This arrangement provides the benefit ofbeing capable to dispense a repeater 30 onto a support surfaceunsuitable for landing due to debris, slope, sticky substances that mayimpede takeoff, etc.

The dispensing hole 72 may subtend from 30 degrees to 120 degrees of thetray 71. The tray 71 may be adapted to hold from 2 to 11circumferentially spaced repeaters 30. The perimeter lip 73 may have aheight of at least one half of the thickness of the repeater 30, but notbe so tall as to impair loading of the repeaters 30 as needed for themission. The present invention provides the benefit that the same drone60 may be loaded with different repeaters 30 as best suited for aparticular mission.

Referring to FIG. 7 , a radial arm 74 extends from a proximal endfixedly joined to the shaft 68 to a distal end juxtaposed with the lip73. The shaft 68 rotates the arm 74 in response to rotational input fromthe shaft 68 motor 35. The radial arm 74 has a front side which is thedirection of forward arm 74 rotation and a backside opposed thereto. Inthis embodiment, having the rotatable arm 74, the front side of the arm74 contacts each repeater 30 to be dispensed in turn.

The movement of the arm 74 about the longitudinal axis LA urges the atleast one repeater 30 to circumferentially index and reposition relativeto the tray 71. The arms 74 shown in the figure are counterclockwiserotatable in a forward direction. The opposite direction (clockwise asshown) is referred to as the reverse direction.

The arm 74 is preferably concave in the forward direction of rotation,to propel the at least one repeater 30 in the rotation direction,reducing radial stray to minimize undue drag from either the shaft 68 orthe inside of the upstanding lip 73. The radius of the arm 74 maydecrease as the distal end is approached. This structure provides thebenefit that the arm 74 may help to dislodge a repeater 30 if it islodged against the inside of the lip 73.

A microprocessor 64 indexes the shaft 68, and thus the radial arm 74 apredetermined rotation arc approximately corresponding to the diameterof a round repeater 30. The arc may correspond to one position 75, witheach repeater 30 and the dispensing hole 72 comprising one position 75.By way of nonlimiting example, if five repeaters 30 arecircumferentially disposed on the tray 71, there are six total positions75—one for each repeater 30 and one for the dispensing hole 72. Eachposition 75 of the tray 71 subtends 60 degrees and each index of theshaft 68 and arm 74 one position 75 would likewise subtend 60 degrees offorward rotation.

A dedicated servomotor 35 attached to the flight control board may beused to rotate the shaft 68. Preferably the servomotor 35 has a stalltorque of at least about 2 Kg-cm, a response speed of at least 0.1sec/60 degrees, an operating voltage of 4-6 VDC and a deadband widthabout 5 microseconds or less. A Tower Pro MG9OS Micro Servo availablefrom American Robotic Supply of Pikeville, N.C. has been found suitable,with either the 4.8V or 6V model being judged as suitable.

Referring back to FIG. 6A and FIG. 6B, upon command from the basestation 21 the first rotation indexes the radial arm 74 one position 75and dispenses the first repeater 30 through the hole 72. The remainingrepeaters 30 advance one position 75, with the second repeater 30 beingcircumferentially adjacent the dispensing hole 72. Likewise, uponcommand from the base station 21, the second rotation advances the arm74 again, and dispenses the second repeater 30. Each of the otherrepeaters 30 advances in turn. This process is continued until thedesired number of repeaters 30 is dispensed.

If the repeaters 30 have a diameter to height aspect ratio of about 1 toabout 8, and preferably about 1.5 to about 5, prophetically unintendedinversion during dispensing is reduced. A repeater 30 having a diameterof 7 centimeters and height of 4.5 centimeters has been found to workwell without inversion when dispensed through a dispensing hole 72having a diameter of 7.4 centimeters and a tray 71 having a diameter of20.3 centimeters. If a non-round repeater 30 is used, the aspect ratiois taken as the ratio of the minor footprint dimension to the maximumthickness.

The present invention advantageously dispenses repeaters 30 in anupright position 75 and onto almost any type of generally horizontalsurface. If the repeaters 30 are dispensed edgewise or upside down,operation will likely be impaired. For example, if the repeaters 30 aredispensed right side up, relocation and orientation is possible, asdescribed below.

Furthermore, typical repeaters 30 have a heading angle and correspondinglongitudinal axis RA which are preferably oriented to best transceivethe signals. The repeaters 30 may be loaded onto the tray 71 with theheading angles in a predetermined orientation. With the structure ofthis invention, the repeaters 30 generally do not rotate about their owncentral axis during indexing and dispensing.

For example, the repeaters 30 may be loaded with the heading angles ofthe respective repeaters 30 radially oriented towards or away from thecentral shaft 68. Thus the present invention advantageously provides thebenefits of both right side up dispensing and providing a preferredazimuthal orientation for the heading angle.

If desired, the tray 71 may have a circumferential upstanding tongue andthe bottom of the repeater 30 may have a complementary groove into whichthe tongue is slidably and removably fitted during loading. Thisstructure provides the benefit that as the repeater 30 is indexed aroundthe tray 71, the heading angle of the longitudinal axis RA of therepeater 30 is known at all times. In another embodiment the tray 71 mayhave two groves, each concentric with the longitudinal axis LA. Thegrooves may be complementary to the legs 34 of the repeaters 30, so thatthe repeater 30 rides in the grooves until dispensed through the hole.This arrangement provides the further benefit that the repeater 30 canuse the existing legs 34 for the dual purposes of positioning while inthe tray 71 and locomotion after dispensing.

If desired, the dispensing assembly 70 of the drone 60 may comprise anoptional plurality of any reasonable number of vertically stacked trays71. This embodiment provides the benefit of decoupling payload,particularly the repeater 30 capacity, from the footprint. In thisembodiment, more repeaters 30 can be carried without increasing the sizeof the footprint.

In such an embodiment, all of the trays 71 are mutually concentric withthe central shaft 68. Each tray 71 has the aforementioned dispensinghole 72, the constraining upstanding perimeter lip 73 and a shaft 68driven, dedicated radial arm 74 for indexing and dispensing of therepeaters 30 through a dispensing in that tray 71. The trays 71 may belongitudinally separated from adjacent trays 71 by a distance of 1.2 Tto 2 T to prevent misalignment of the repeater 30 during the gravitydrop from the superjacent tray 71, where T is the maximum thickness ofthe repeater 30 and the drop is measured from the lower surface of thesuperjacent tray 71 to the upper surface of the subjacent tray 71.

In this embodiment, the top tray 71 may be considered as the first tray71 and dispenses the repeaters 30 through the dispensing hole 72, asdescribed above, down to the second tray 71. The second tray 71 may bespaced from the first tray 71 in the longitudinal direction. When thelongitudinal axis LA is vertical, the second tray 71 is directly belowthe first tray 71, an optional third tray 71 is directly below thesecond tray 71, and so on until the bottom tray 71 is reached. In thisembodiment, the first tray 71 dispenses repeaters 30 onto the secondtray 71, the second tray 71 dispenses repeaters 30 onto the third tray71, if present, etc. The lower or lowest tray 71 dispenses the repeater30 onto the desired support surface of the environment.

In such an arrangement, preferably each tray 71 has the same number ofpositions 75 to improve balance around the shaft 68. Each tray 71 has acircumferentially disposed first position 75. The first position 75 isimmediately behind the dispensing hole 72, so that upon indexing theradial arm 74 in the forward direction a first repeater 30 can bedispensed therethrough. The second position 75 advances to the firstposition 75 upon indexing one rotation arc. Another index of the radialarm 74 rotates that position 75 to the dispensing hole 72 to dispenseanother repeater 30 therethrough, until the last position 75 interceptsthe dispensing hole 72 to deliver a repeater 30 therethrough. In asingle tray 71 embodiment the repeater 30 is dispensed onto a supportsurface in a hostile environment. In a plural tray 71 embodiment, therepeater 30 may first be dispensed from its initial payload tray 71 to asubjacent tray 71, then later dispensed onto the support surface.

Referring to FIG. 8 in a plural tray 71 embodiment the dispensing hole72 on the first (top) tray 71 may be in a first circumferential position75. The dispensing hole 72 of the first tray 71 is longitudinally(vertically) aligned with the last position 75 of the second tray 71.The dispensing hole 72 of each tray 71 is then vertically aligned withthe last position 75 of the subjacent tray 71 so that maximum repeater30 capacity is achieved for each tray 71.

For example, in a triple tray 71 embodiment having arms 74 which rotatecounterclockwise in the forward direction, the dispensing hole 72 in thetop tray 71 may be disposed at a first dispensing position 75. Thedispensing hole 72 of the second tray 71 is preferably longitudinallyaligned one position 75 counterclockwise relative to the hole of thefirst tray 71, to correspond to the last dispensing position 75 of thesecond tray 71 and maximize utilization of tray 71 capacity. Thedispensing hole 72 of the third tray 71 is likewise aligned one position75 counterclockwise relative to the hole of the second tray 71 and soon.

Similarly, the arm 74 of each tray 71 leads the arm 74 of thesuperjacent tray 71 one position 75. In the forward counterclockwiseexample, the arm 74 of the second tray 71 leads the arm 74 of the firsttray 71 one position 75 counterclockwise of the arm 74 of the first tray71 and so on.

Each tray 71 has the respective arm 74 behind the first repeater 30 sothat the first repeater 30 of each tray 71 is indexed as dispensingoccurs. This geometry advantageously provides that as the first tray 71dispenses its repeater 30 onto the last position 75 second tray 71, thesecond tray 71 automatically and likewise dispenses its first repeater30 onto hostile environment, and so on. This arrangement provides thebenefit that the first tray 71 is always fully loaded and ready fordispensing the repeaters 30 previously carried by the trays 71 above.

If desired for increased capacity, the drone 60 may have two or moreparallel shafts 68, each shaft 68 having a respective and dedicated tray71 or a respective dedicated vertical stack of trays 71. The shafts 68would alternatingly index and dispense the repeaters 30 from therespective tray 71 to maintain balance. Such a drone 60 wouldprophetically have six or more copters for adequate lift.

One of skill will understand that the repeaters 30 are likely dispensedin series with the first repeater 30 being closest to the base station21, the second repeater 30 being dispensed in direct communication withthe first repeater 30, etc. But one of skill will likewise recognizethat the changing conditions of a hostile environment may dictatedispensing the repeaters 30 in a sequence out of order from the line ofsight. The repeaters 30 may be mutually identical, providing the benefitof simplicity and economy of design. Alternatively, some of therepeaters 30 may be mutually different, providing the benefit thatdifferent repeaters 30 may be deployed as most suitable for a particularrepeater 30 station during the mission.

In an alternative embodiment, the dispensing assembly 70 may have alongitudinally coaxial shaft 68 assembly, comprising a stationary outershaft 68 and an axially rotatable inner shaft 68. The radial arm 74 maybe joined to the outer shaft 68 in nonrotatable and fixed relationship.The tray 71 may be joined to the inner shaft 68, which in turn is joinedto the servomotor 35. In this embodiment, the tray 71 is either loadedwith the repeaters 30 such that, or is rotated such that, the repeaters30 are eventually dammed into a set position 75 by the fixed radiallyarm 74. The repeaters 30 contact the backside of a stationary arm 74. Inboth embodiments one of the tray 71 and arm 74 moves relative to theother.

The tray 71 is then indexed with respect to the nomoving repeaters 30,so that the tray 71 slides under the repeaters 30 until the dispensinghole 72 is coincident a repeater 30. The repeater 30 is then gravitydispensed through the hole. At the next repeater station the tray 71 isindexed again and the second repeater 30 is gravity discharged throughthe dispensing hole 72. This process is repeated until the desirednumber of repeaters 30 is dispensed into the hostile environment.

In an alternative embodiment the tray 71 may have two diametricallyoffset dispensing holes 72 and two diametrically offset dispensing arms74. This embodiment provides the benefit that two repeaters 30 may besimultaneously dispensed in mutually close proximity for redundancy andreducing dispensing time. In an alternative embodiment, the tray 71 maybe slightly concave upwardly shaped, to reduce friction of the repeaters30 against the perimeter lip 73. Plural trays 71 may be of the samediameter or of different diameters, as desired.

Referring to FIG. 9A and FIG. 9B, each repeater 30 has a shell 31defining a longitudinal axis RA and protectively enclosing a battery 36powered transceiver 37 and microprocessor 64, which may be an integratedunit. The shell 31 functions as a frame 66, holding the components ofthe repeater 30 in fixed relationship for operation during the mission,particularly upon being delivered to a respective repeater station. Thecomponents of the repeater 30 may be adhesively joined to the shell 31or be disposed in tight sockets complementary to the shape of thecomponent. The repeater shell 31 preferably has a round footprint toavoid misalignment during dispensing and enable maneuvering near a wallor other obstruction. The shell 31 may have an openable configurationfor protectively encasing the microprocessor 64 and other componentsduring use and for removal and restoration of components duringmaintenance. The shell 31 may be made of carbon fiber or any suitableplastic, such as Nylon, ABS or PVC.

The diameter of the shell 31 is complementary to the radial width of thetray 71, so that the repeater 30 may move in circular fashion to thedispensing hole 72. When the repeater 30 is loaded onto the tray 71, thelongitudinal axis RA of the repeater 30 and longitudinal axis LA of thedrone 60 are mutually perpendicular.

Referring to FIG. 9C and FIG. 9D, a pluralities of legs 34 depend fromthe bottom of the shell 31 to interface with the tray 71 of the drone60. The legs 34 are cantilevered from a proximal end at the shell 31 andextend to a distal end which rests on a support surface, such as a flooror table. The powered legs 34 are preferably tapered to optimize thestrength to weight ratio. At least the forward legs 34 are rearwardlyangled to define a forward direction and rearward direction. The rearlegs 34 of the repeater 30 may optionally be angled as well. Therearward angle of the legs 34 relative to the support surface provides aratcheting affect for forward locomotion caused by oscillations of thelegs 34 in response to vibrations induced by a respective vibratorymotor 39.

The forward legs 34 may be rearwardly angled from about 16 to about 30degrees, preferably about 20 to about 26 degrees and more preferablyabout 23 degrees relative to a horizontal support surface. A repeater 30having two forward pods 33, each with four identical tapered legs 34,with the legs 34 rearwardly angled in the longitudinal direction 23degrees and 9 mm long has been found suitable for a repeater 30 weighing75 grams and having two vibratory motors 39 of approximately 0.25 wattseach.

The legs 34 may be straight, as shown. Optionally the legs 34 may becurved so that induced vibrations may cause the legs 34 to deflect inthe direction of curvature, prophetically improving locomotion. Thedistal ends of the legs 34 may optionally be rubber coated to providefriction against the support surface. The vibratory motors 39 or piezodevices, such a s piezoelectric crystal 40, may excite the forward legs34 at a fundamental resonant frequency or a harmonic thereof,prophetically resulting in even greater locomotion.

The legs 34 are clustered into spaced apart pods 33, with each pod 33comprising plural legs 34. The pods 33 of legs 34 may be distributedwith two spaced forward pods 33 and a single rearward pod 33 defining atriangular configuration and preferably forming a planar triangle. For acircular repeater 30, the centroid of the two forward pods 33 defines achord therebetween. The longitudinal axis RA of the repeater 30 isperpendicular to this chord. Plural forward pods 33 may be paired topreferably symmetrically straddle the longitudinal axis RA to providefor operational movement in any direction, particularly left-rightmovement relative to the longitudinal axis RA. While an embodimenthaving two forward pods 33 of four legs 34 is shown, one of skill willrecognize the invention is not so limited. The repeater 30 may compriseany plurality of forward pods 33 of one or more legs 34, and one or morerearward pods 33 of one or more unpowered legs 34.

A single rearward unpowered leg 34 may be provided and comprise therearward pod 33. The at least one rearward leg 34 may be generallyperpendicular to the support surface or may be rearwardly oriented toassist with the ratcheting effect against the support surface. Legs 34in the rearward pod 33 may be longitudinally aligned and coincident thelongitudinal axis RA, disposed in a regular polygonal configuration orany other suitable configuration.

Referring to FIG. 9E, a battery 36 powered vibratory motor 39 isoperably associated with each forward pod 33 of legs 34. Each vibratorymotor 39 is mounted near the proximal end of a respective forward pod 33and has a rotatable shaft azimuthally angled relative to thelongitudinal axis RA to form an included angle of about 30 to about 45degrees, preferably about 33 to about 41 degrees and more preferablyabout 37 degrees therebetween. The centroid of the shell 31 and the endsof the chord define an included angle ranging from 70 to 80 degrees. Theshafts of the vibratory motors 39 are preferably, but not necessarily,parallel to the support surface with each vibratory motor 39 mounteddirectly over the respective leg 34.

The vibratory motor 39 and respective pod 33 comprising at least one leg34 may be disposed in a common housing joined to the underside of thefloor pan of the repeater 30. The housing and floor pan are consideredpart of the shell 31 and may be formed integrally with other portions ofthe shell 31. This configuration provides for focus of the vibrationsfrom the vibratory motor 39 to the legs 34, reducing damping by therepeater 30 shell 31 and prophetically increasing efficiency. One willunderstand the underside of the repeater 30 floor pan faces directlytowards the support surface.

The vibratory motor 39 is preferably a DC button motor to conservespace, payload weight and power draw from the battery 36. The vibratorymotor 39 may range from 2V to 5V, and is preferably about 3V providingfrom 0.1 to 0.6 watts, and preferably from 0.24 watts to 0.32 watts.Each vibratory motor 39 rotates an eccentric load at 1500 rpm to 20000rpm to induce the vibrations at the associated pod 33 of legs 34. ABestTong 10,000 rpm, 10 mm×2 mm flat button-type DC vibratory motor 39has been found suitable. For a repeater 30 weighing about 70 to about 80grams, this arrangement advantageously provides a power to weight ratioof about 3 to about 5 milliwatts/gram. Such an embodiment hasadvantageously provided for a repeater 30 which travels approximately 22mm/sec with both vibratory motors 39 simultaneously driven.

Prophetically a piezoelectric device 40 may be used in addition to or inplace of the eccentric load vibratory motor 39 to induceoscillations/vibrations in the legs 34. A piezoelectric devicecomprising a motor or piezoelectric crystal 40 prophetically providesthe benefits of higher frequency vibrations for increased speed, and thefurther benefit of being able to select and tune a specific and precisevibration for a given repeater 30 geometry. A repeater 30 which travelsat speeds of about 15 to about 30 mm/sec is believed to be suitable andnot place undue power demands on the battery 36 with both vibratorymotors 39 or both piezoelectric crystals 40 simultaneously driven.

If the two front vibratory motors 39 are simultaneously activated, therepeater 30 will move forward, substantially along the longitudinal axisRA. Activating only one vibratory motor 39 turns the repeater 30 towardsthe direction of the other, or still, vibratory motor 39. By selectivelyand independently activating the first vibratory motor 39 associatedwith the first legs 34 and/or the second vibratory motor 39 associatedwith the second legs 34 the repeater 30 can be advantageously andremotely maneuvered in the hostile environment. Maneuvering includesboth a change in positional location and a rotational change inazimuthal angle. This arrangement provides for remote placement andorientation of the repeater 30 as may be helpful to maintain line ofsight communication or avoid impending hostility.

One of skill will recognize that movement in any direction is subject tothe slope of the support surface, debris, etc. Likewise one willrecognize that any suitable number of pods 33 may be used in variousembodiments. For example, a repeater 30 may have four pods 33 of legs34, in a rectangular configuration. Each of the four pods 33 may have anassociated means for inducing vibration independent of any other pod 33to provide locomotion a desired direction.

In the prototype system, the base station 21 controls the repeaters 30in an open loop control and commands that are sent to the repeaters 30are expected to be correctly executed. The base station 21 registers theorientation of the repeater 30 and commands it to turn as necessary toadvance in the desired direction. As the repeaters 30 move about, thebase station 21 tracks where the repeaters 30 are located, based on themovements as commanded. Prophetically, the repeaters 30 may engage asensor, such as a magnetic compass, to determine heading angle. Thedrone 60 preferably deposits each repeater 30 with a known heading, sothat the communication system 20 may robustly track changes in position.

The microprocessor 64 and vibratory motors 39 are preferably powered bya common battery 36. A single cell 3.7 V Li-Po battery 36 is suitablefor the embodiment described herein. Preferably the battery 36,microprocessor 64 and vibratory motors 39 are hardwired together.

The microprocessor 64 controls the signals to the vibratory motors 39 asdesired to move the repeater 30 in order to optimize communication. Themicroprocessor 64 also controls receipt and transmission of signalsbetween repeaters 30 through a WiFi chip. A WiFi mesh connects therepeaters 30 with a SSID so that a common code and network areavailable. The microprocessor 64 software may be written in Arduino Clanguage. The microprocessor 64 may have a 3.3V regulator with 500 mApeak current output, CP2104 USB-Serial converter onboard with 921600 maxbaud rate at 80 MHz and 4 MB of FLASH (32 MBit). An Adafruit ESP8266Feather Huzzah board has been found suitable.

The rearward pod 33 is not used for locomotion and may comprise a singleleg 34 or plural legs 34. The leg 34 of the rearward pod 33 may beperpendicular to the support surface and be disposed on the longitudinalaxis RA. The leg(s) 34 of the rearward pod 33 may be powered by adedicated vibratory motor 39 or piezoelectric crystal 40, but arepreferably unpowered.

A key performance metric is network signal strength. The position andorientation of the repeater 30 are the means to achieving a robust andadequate wireless network. The base station 21 can command a repeater 30to move and assess whether the signal strength of the network improvedor degraded and command the repeater 30 to move in the direction thatimproves the network signal processing.

Referring to FIG. 9F, the shell 31 of the repeater 30 may beaesthetically configured to resemble common items or backdrops which maybe indigenous to or commonly found in the particular hostile environmentunder consideration. Such embodiments may be tailored to variousscenarios expected to be encountered throughout the mission. Thisflexibility provides that the tray 71 may hold a plurality of likerepeaters 30 or a selection of aesthetically different repeaters 30.

By way of non-limiting example from left to right, a first repeater 30shell 31 may resemble a rock as might be found outside of the hostileenvironment and having a generally oval footprint. A second repeater 30shell 31 may resemble a paver stone as may be found in landscapingjuxtaposed outside a building and having a generally square footprint.Other repeater 30 shells 31 may resemble a common items found inside abuilding. For example, a third repeater 30 shell 31 may be disguised asa smoke detector and a fourth repeater shell may resemble a saucer asmay be found inside a building of interest. If desired, one or morerepeaters 30 may have lamps 38 for illumination of the immediatesurroundings when the drone 60 or forward agent 25 are near. All of therepeaters 30 in the system may have shells 31 disguised as describedherein or only a subset of the plurality of the repeaters 30 may havesuch a shell 31.

Referring to FIG. 10A and FIG. 10B, the control algorithm may reside onthe base station 21, with repeater 30 placement commands being sent tothe drone 60 through the wireless mesh network, as are any subsequentcommands for the repeaters 30 to relocate. Commands from the basestation 21 may be sent to the drone(s) 60 and repeater(s) 30 via awireless signal having a frequency of 30 Hz to 300 GHz, and preferablyhaving a Bluetooth frequency of 2.4 GHz or a frequency of 5 GHz.

Referring to FIG. 10B, the repeater 30 network control algorithmoperates by continuously monitoring network signal strength betweenrepeaters 30. Each repeater 30 separately assesses the strength ofsignal coming from both adjacent repeaters 30. Therefore, repeater 30“k” quantifies the strength of the connection from k−1 to k and k tok+1. All of these values are continuously shared with the entire meshnetwork, including the drone 60 and the base station 21. In nominaloperation, the base station 21 operates the repeater network controlalgorithm by evaluating the signal strength data it receives. In theevent that a weak signal is detected between two nodes of the network,the base station 21 sends commands to the involved repeaters 30 to healthe network.

If a weak connection is detected between repeater 30 k and repeater 30k+1 the algorithm first instructs repeater 30 k+1 to reorient theazimuth in an arbitrary direction. The base station 21 monitors thesignal strength as the repeater 30 reorients. If the signal strengthimproves, the repeater 30 will be directed to continue moving until thenetwork signal strength is satisfactory. If the signal strengthdegrades, the repeater 30 will be commanded to move in the oppositedirection. If azimuth reorientation is ineffective, the base station 21will command repeater 30 k+1 to change position, first by moving towardsrepeater 30 k, and if that is unsuccessful, then moving away fromrepeater 30 k. If these basic actions fail to improve the signalstrength, other combinations of rotation and movement are undertaken,such as reorienting the repeater 30, then changing position or viceversa.

In an alternative embodiment, the algorithm may additionally reside onthe drone 60 or on each of the base station 21, drone 60 and pluralityof repeaters 30. In such embodiment, the success of the algorithm is notdependent upon an intact mesh network, as repeaters 30 could dynamicallyaccommodate damage to the network by adjusting position, even if cut offfrom the base station 21. In this embodiment, the repeaters 30 initiallytake commands from the base station 21 algorithm as default. But ifcontact with the base station 21 is lost, as may be indicated by notreceiving an occasional ping from the base station 21, the repeater 30could revert to commands from its own algorithm.

In operation, as the drone 60 travels through the hostile environmentusing the algorithm according to the present invention, the drone 60dispenses plural repeaters 30 at a like plurality of repeater stationsaccording to two criteria: not to exceed maximum separation distance forthat communication system 20 and at corners. Preferably, repeaters 30are consecutively positioned at predetermined separation distances whichrange from 50 to 70 percent of the maximum wireless communication rangebetween successive repeaters 30 for buffer. This range provides a safetymargin in the mesh network, and allows for future self-healing of thenetwork if a repeater 30 becomes inoperable. Spacing the repeaters 30too close together may require excessive quantities of repeaters 30,complicating the mission. Spacing the repeaters 30 too far apart canjeopardize communications.

Additionally when a repeater 30 is dispensed when the drone 60encounters a corner, in order to maintain line of sight between thesuccessive repeaters 30. Recognition of corners is based upon thresholddeviations in the movement of the drone 60 in an X-Y plane, indicatingthat the drone 60 is moving in a path having a vector component 90degrees to the previous path, and has thus turned a corner. Stairs andother elevation changes may be recognized based upon thresholddeviations in the Z direction, it being understood the X, Y and Zdirections are mutually perpendicular.

The repeaters 30 may be disposed in a single series from the basestation 21 to a first repeater station, to a second repeater station toa plurality of additional intermediate repeater stations and so on untilthe repeater 30 at the last repeater station is in communication withthe forward agent 25. Optionally, the series of repeaters 30 may branchand provide two different and alternative paths from the base station 21to the forward agent 25 for redundancy. Alternatively, the series ofrepeaters 30 may branch and lead to two or more forward agents 25 at twoor more different locations in the hostile environment.

In the event of an unexpected repeater 30 failure, adjacent and nearbyrepeaters 30 may be repositioned to accommodate. Alternatively,repeaters 30 may be positioned based upon attenuation of signalstrength. The aforementioned buffer allows the repeaters 30 toreposition and still maintain communication with either adjacentrepeater 30. This capability advantageously prevents the entire networkfrom collapse based upon a single point of failure.

Upon failure of a repeater 30, only those repeaters 30 between the basestation 21 and the point of failure initiate a self-healing response.This arrangement allows an operator at the base station 21 to be able toconstantly provide input to the communication system 20 as needed.

Upon detecting a fault at an intermediate repeater 30 between said firstrepeater 30 and said nth repeater 30, the algorithm instructs theintermediate repeater 30 to first move in either the X direction or Ydirection, whichever is greater in relation to the original position ofthe preceding repeater 30, to reestablish communication with thepreceding repeater 30. The algorithm may then instruct the intermediaterepeater 30 to azimuthally reorient to optimize the communicationsignal.

The first repeater 30 needs to only be programmed with its position upondelivery to the first repeater station RS1 and the position of the basestation 21 to reposition and maintain an unbroken communication signalin the event of signal fault or undue attenuation. Each repeater 30after the first repeater 30 need only be programmed with its ownposition and the position of the respective preceding repeater 30 tomaintain communication if the original placement of that repeater 30, ordynamic conditions, provides a signal fault or undue attenuation.Therefore each repeater 30 may be dynamically programmed with itsposition only relative to a preceding repeater 30 or to the base station21 as the case may be. This algorithm advantageously simplifiesoperations by obviating each repeater 30 to store values for itspositions relative to the positions of every other repeater 30 in thenetwork.

Referring to FIG. 11A, Matlab software, available from The MathworksInc. of Natick, Mass., has been found suitable for simulating repeater30 positioning and repositioning in the event of signal failure. FIG.11A shows a simulation 80 with initial simulated positions of 12repeaters 30, R1, R2, R3 . . . Rn. The positions of the repeaters 30compensate for an obstruction 81 in the middle of the simulation 80field. The obstruction 81 may be debris, a plurality of corners, etc. Afailure of repeater 30 R3 is assumed.

Referring to FIG. 11 B, the simulation 80 compensates for the failure ofrepeater 30 R3 by adjusting the positions of repeaters 30 R1 and R2through command signals. The simulation 80 shows adjustment ofdownstream repeaters 30 is not needed to maintain communication fromrepeater 30 R1 to repeater 30 Rn.

In another embodiment the invention comprises a non-transitory computerreadable medium suitable for and configured to carry out thecomputations and determinations of any of the foregoing, including onlyas limited by the claims below, algorithms, calculations, estimates suchas but not limited to Kalman estimates, iterative/recursive exercises,solving of equations/inequalities and determinations of any of theparameters listed in the claims below.

Exemplary non-transitory computer readable media according to thepresent invention are physical, transferable, reproducible, may compriseall computer readable media except for a transitory propagating signaland particularly include flash drives, CD's, DVDs, internal/externalhard drives, more particularly internal/external solid state harddrives, and further exclude

RAM, volatile memory requiring power for data storage, signals andeffervescent carrier waves. In an alternative embodiment, transitorycomputer readable media may also be used.

To the extent that the figures illustrate diagrams of the functionalblocks of the various embodiments, the functional blocks are notnecessarily indicative of the division between hardware circuitry. Thus,for example, one or more of the functional blocks (e.g., processors ormemories) may be implemented in a single piece of hardware (e.g., asignal processor or a block of random access memory, hard disk, or thelike) or multiple pieces of hardware. Similarly, the programs may bestandalone programs, may be incorporated as subroutines in an operatingsystem, may be functions in an installed software package, and the like.The upper limit of any range may be combined with the lower limit of anyrange for that same parameter and vice versa. It should be understoodthat the various embodiments are not limited to the arrangements andinstrumentality shown in the drawings.

What is claimed is:
 1. A method of establishing a communication systemin a hostile environment, said method comprising the steps of: providingan operably maneuverable drone carrying a plurality of independentlydepositable repeaters; providing a base station for controlling saiddrone; controlling said drone from said base station to maneuver saiddrone to a plurality of successive repeater stations, in turn, anddepositing a like plurality of repeaters thereat, so that a saidrepeater is disposed at each of said repeater stations to establish amesh of said repeaters; said plurality of repeater stations comprising,in order of deposit, a first repeater station having a first repeater,and at least a second repeater station having a second repeater, inorder, until a nth repeater station having an nth repeater in directcommunication with said drone is established, whereby said drone canwirelessly transmit a signal from a location of interest to said nthrepeater at said nth repeater station, from said nth repeater to a n−1repeater at an n−1 repeater station, in turn until said signal isreceivable by said first repeater; and said signal being transmittablefrom said first repeater to said base station whereby an operator atsaid base station can interpret and act upon said signal.
 2. A methodaccording to claim 1 further comprising the step of repositioning atleast one said repeater in an X-Y plane to improve the signaltransmission thereof after said repeater is deposited at a respectiverepeater station.
 3. A method according to claim 2 further comprisingthe step of azimuthally orienting at least one said repeater to improvethe signal transmission thereof after said repeater deposited at arespective repeater station.
 4. A method according to claim 3 whereineach said repeater is X-Y repositionable and is azimuthally orientableindependent of the rest of said repeaters in said plurality ofrepeaters.
 5. A method according to claim 4 further comprising the stepof determining the position of each said repeater relative to arespective preceding repeater, so that a said repeater can move in saidX-Y plane relative to said preceding repeater to maintain signalcommunication therewith.
 6. A method according to claim 5 furthercomprising the step of detecting a fault at an intermediate repeaterdisposed between said first repeater and said nth repeater and in saidmesh of said plurality of repeaters, and autonomously moving saidintermediate repeater in the X-Y plane to maintain communication withsaid preceding repeater.
 7. A method according to claim 6 furthercomprising the step of autonomously azimuthally rotating saidintermediate repeater to optimize said signal.
 8. A method according toclaim 5 wherein each said repeater after said first repeater isprogrammed with the position of that said repeater and with the positionof a respective said preceding repeater and is not programmed with theposition of any other repeater.
 9. A method of establishing acommunication system in a hostile environment, said method comprisingthe steps of: providing an operably maneuverable drone carrying aplurality of independently deliverable repeaters; providing a basestation for controlling said drone; controlling said drone from saidbase station to maneuver said drone along a path; delivering a firstrepeater, said first repeater being in communication with said basestation; delivering a plurality of successive repeaters after said firstrepeater, in succession, so that each said successive repeater is incommunication with a respective preceding said repeater and no otherrepeater to establish a communication network of said repeaters; saidplurality of repeaters comprising, in order of delivery, a firstrepeater and a plurality of repeaters thereafter, in succession, until anth repeater in direct communication with said drone is established;establishing the position of each said repeater after said firstrepeater relative to a respective preceding said repeater and notrelative to any successive said repeaters; establishing the position ofsaid first repeater relative to said base station; wirelesslytransmitting a signal from a location of interest to said drone, fromsaid drone to said nth repeater, from said nth repeater to a n−1repeater, in turn until said signal is received by said first repeater;and transmitting said signal from said first repeater to said basestation whereby an operator at said base station can interpret and actupon said signal.
 10. A method according to claim 9 further comprisingthe step of transmitting a forward signal from said base station to saidfirst repeater, from said first repeater to each said successiverepeater, in turn, to a nth repeater; and transmitting said forwardsignal from nth repeater to said drone when said drone is at a locationof interest.
 11. A method according to claim 10 further comprising thestep of transmitting a return signal from said drone to said basestation, said return signal comprising information relevant to thehostile environment.
 12. A method according to claim 11 furthercomprising the step of controlling at least one said repeater from saidbase station to reposition said at least one repeater after saidrepeater is delivered by said drone.
 13. A method according to claim 12comprising the step of moving at least one said repeater in an X-Y planeand azimuthally reorienting at least one said repeater.
 14. A portablecommunication system for use in a hostile environment, saidcommunication system comprising: an operably maneuverable drone forcarrying a plurality of independently deliverable repeaters; a pluralityof repeaters carried by said drone and deliverable from said drone insuccession, so that each said successive repeater may be delivered inline of sight communication with a respective preceding said repeater;and a base station for controlling a flight path of said drone and forcontrolling delivery of each said repeater at a desired location.
 15. Aportable communication system according to claim 14 wherein, upondelivery to a support surface, each said repeater is autonomouslymovable to be in operable line of sight communication with a precedingsaid repeater.
 16. A portable communication system according to claim 15wherein, upon delivery to a support surface, each said repeater isautonomously movable in an XY plane and is azimuthally orientable to bein operable line of sight communication with a preceding said repeater.17. A portable communication system according to claim 16 wherein, upondelivery to a support surface, each said repeater is movable in responseto a command signal from said base station to be in operable line ofsight communication with a preceding said repeater.
 18. A portablecommunication system according to claim 17 wherein each said repeater,upon delivery in succession to said support surface, is programmed withits position and with a position of a respective preceding repeater orsaid base station.
 19. A portable communication system according toclaim 18 wherein each said repeater is not programmed with a position ofa respective succeeding repeater.
 20. A portable communication systemaccording to claim 19 wherein said drone is programmable to send an X-Ycoordinate signal to said base station in real time so that travelaround a corner can be recognized in real time.